哈维氏弧菌引起的条纹海马表皮溃疡综合征的研究

近年来,条纹海马的养殖在我国发展迅速,但由于多种养殖疾病的频繁暴发,严重制约了条纹海马养殖业的健康发展。自2017年以来,我国北方地区在条纹海马的养殖过程中,多次发生表皮溃疡综合征,患病海马游泳能力减弱,皮肤大面积溃疡,同时伴随烂尾症状,解剖后发现其肠道发白,肝脏及鳃颜色暗淡,死亡率较高,给海马养殖业造成巨大的经济损失。本研究从患病条纹海马的溃烂肌肉及肠道中分离出13株优势菌株,经回归感染实验证实菌株HDM-2可引起条纹海马出现表皮溃疡综合征的类似症状,且半数致死量(LD_(50))约为2.89×10~8 CFU/mL。为确定菌株HDM-2的分类地位,采用生理生化及基于16S rDNA的分子生物学方法对其进行鉴定,结果显示,HDM-2为哈维氏弧菌;为了解菌株HDM-2的菌体特征,采用透射电镜(TEM)对菌株HDM-2进行观察,结果显示,HDM-2为周生鞭毛,有荚膜,大小约2.20μm×4.75μm;为获知HDM-2的抗生素敏感性,采用纸片扩散法进行药敏试验,结果显示,菌株HDM-2对氟苯尼考和头孢他啶等较敏感;患病条纹海马的组织病理学研究表明,菌株HDM-2对条纹海马的皮肤、肝脏以及鳃组织损伤较严重。本文可为条纹海马表皮溃疡综合征的防治及深入研究提供基础资料。     

Observation of virus particles in the spleen, kidney, gills and erythrocytes of Atlantic salmon, Salmo salar L., during a disease outbreak with high mortality

An annual disease problem with high levels of mortality in Atlantic salmon, Salmo salar L., on a freshwater farm was investigated. In 2000, mortalities began early in October and peaked in December, being unevenly distributed between tanks. Histopathological changes included severe hyperplasia of gill epithelium, with fusion of secondary lamellae, and extensive necrosis of the haematopoietic centres in the kidney and spleen, the latter being consistent with a diagnosis of phagocytolytic syndrome (PCLS). Moribund fish were anaemic, with multiple, circular basophilic inclusion bodies, 1–2 μm in diameter and suggestive of erythrocytic inclusion body syndrome (EIBS), being observed on blood smears. Thin section electron microscopy (EM) revealed primarily membrane-bound aggregates of non-enveloped virus particles (73 ± 7 nm) with an electron dense core (35 ± 3 nm) in spleen, kidney and gill tissue and the erythrocytes therein. These particles had morphology and distribution consistent with those previously described separately for both EIBS and PCLS. Virus isolation attempts in a wide range of cell lines were unsuccessful. In the absence of suitable alternative infectious or environmental explanations, it is postulated that the aetiology was primarily viral, with possible contributory secondary environmental factors. It is further hypothesized that the agents of EIBS and PCLS may be the same or closely related viruses.     

卤虫携带白斑综合征病毒的研究

卤虫是是,蟹苗种培育的关键动物性饵料,查清其能否携带白斑综合征病毒,对培育健康苗种至关重要。2002年7月至10月,自盐田中取野生卤虫,经暂养后选20尾抱卵雌虫,每尾置1个烧杯中,投喂单胞藻,产卵后取出亲体;20d后,每个烧杯中取5尾子一代个体,利用巢式体外DNA扩增技术对亲体和子一代成体进行WSSV病毒检测,检测结果显示：卤虫中可扩增出特异性的,与引物设计吻合的DNA片段;DNA测序分析表明,扩增片段的DNA序列与白斑综合征病毒序列一致;野生卤虫携带白斑综合征病毒的阳性率为58%,实验条件下野生卤虫后代的阳性率为43%,同一家系中,亲代与子代携带病毒的情况不完全一致,不能确实白斑综合征病毒可否通过繁殖,在卤虫世代间进行垂直传播,研究结果表明：卤虫很可能是白斑综合征病毒的携带者,苗种培育和养殖期间投喂卤虫可能造成虾,蟹感染白斑综合征病毒,卤虫检疫是培育健康苗种的关键措施。     

对虾白斑综合征病毒(WSSV)高分子量结构蛋白的分离

采用蔗糖密度梯度离心从患病对虾组织中提取WSSV,应用SDS-PAGE对WSSV结构蛋白进行了分析。采用12％分离胶,将WSSV样品煮沸5min,应用SDS-PAGE分离了WSSV的中低分子量结构蛋白,并将该结果与其他学者已发表的结果进行了比较。首次通过延长样品煮沸时间,采用8％分离胶,应用SDS-PAGE分离到了WSSV100kD以上的13条高分子量结构蛋白,计算出了每条蛋白带的分子量及其在总蛋白中的百分含量。其中WSSV高分子量结构蛋白的分离丰富了WSSV的研究范围,对今后深入的研究工作具有重要意义。     

胡子鲶血浆中外源生长激素的代谢动力学

采用草鱼生长激素夹心式酶联免疫吸附测定法（ＥＬＩＳＡ）研究了重组鲤生长激素（ｒｃＧＨ）在胡子鲶血浆中的代谢动力学,肌肉注射ｒｃＧＨ（０．２和１μｇ／ｇ）后,胡子鲶血浆ｒｃＧＨ水平迅速升高,于２和３ｈ时达峰值,随后下降,在注射后第２和４天,血浆中检测不到ｒｃＧＨ,腹腔注射ｒｃＧＨ（０．２和１μｇ／ｇ）后,胡子鲶血浆ｒｃＧＨ水平也有同上类似的变动规律,胡子鲶腹腔注射０．５,１和２μｇ／ｇ的ｒｃＧＨ７天     

白斑症病毒在日本对虾体内的感染增殖

用投喂患白斑症病毒病的虾组织人工感染日本对虾稚虾,每日取样,整虾冰冻切片,单克隆抗体的荧光抗体方法,原位观察病毒在虾体内的感染增殖,结果表明：感染后三天内,在感染虾的各组织器官内均未观察到明显的病毒感染的阳性细胞,每四天首先在鳃丝腔内的小量血细胞观察到病毒感染;第五天除血细胞外同时在血窦,鳃上皮组织,皮下组织内观察到,第六天进而在心脏,胃上皮组织内观察到：第七天进一步又在淋巴器官,中肠内观察到,八     

Sex effect on polychlorinated biphenyl concentrations in fish: a synthesis

Polychlorinated biphenyls (PCBs) accumulate in fish primarily via food intake, and therefore, PCBs serve as a chemical tracer for food consumption. Sex differences in PCB concentrations of fish have been attributed to the following three mechanisms: (i) females losing a substantial portion of their PCB body burden during spawning and consequently their PCB concentration is considerably reduced immediately after spawning; (ii) sex differences in habitat utilization leading to sex differences in the PCB concentrations of the prey; and (iii) sex differences in gross growth efficiency, which is defined as growth divided by the amount of food consumption needed to achieve that growth. Based on my analyses and synthesis, mechanisms (i) and (ii) operate in relatively few fish populations, but can lead to mature males having PCB concentrations two to three times higher than mature female PCB concentrations. In contrast, mechanism (iii) operates in all fish populations, but typically, mechanism (iii) results in relatively modest sex differences, with mature males only between 15 and 35% higher in PCB concentration than mature females. In summary, the study of sex differences in PCB concentrations of fish has led to insights into fish behaviour and fish physiology.     

The effects of ration size on migration by hatchery‐raised Atlantic salmon (Salmo salar) and brown trout (Salmo trutta)

Abstract – The possibility to increase the proportion of migrating hatchery‐reared smolts by reducing their food ration was studied. Lake‐migrating, hatchery‐reared salmon (Salmo salar) and trout (Salmo trutta) smolts were either fed normal rations, based on recommendations from the fish‐farming industry, or reduced (15–20%) rations. They were released into the River Klarälven, western Sweden, and followed as they swam downstream to Lake Vänern, a distance of around 25 km. For both Atlantic salmon and brown trout, smolts fed a reduced ration migrated faster than fish fed a normal ration. Furthermore, a higher proportion of salmon smolts fed reduced rations migrated to the lake than fish fed normal rations in 2007 but not in 2006. This difference between years corresponded to greater treatment differences in size and smolt status in 2007 than in 2006. For trout, the proportion of migrating individuals and smolt development did not differ with ration size. Trout migrants fed a normal ration had a higher standard metabolic rate (SMR) than nonmigrants, whereas there was no difference in SMR between migrating and nonmigrating salmon. These results show that it is possible to use a reduced food ration to increase the migration speed of both Atlantic salmon and brown trout and to increase the proportion of migrating Atlantic salmon.     

Stanniocalcin kinetics in freshwater and seawater european eel (Anguilla anguilla)

The kinetics and hypocalcemic potency of stanniocalcin (STC) were examined in freshwater and seawater eels. The secretion rate and the metabolic clearance rate of STC were calculated from the STC disappearance curve after intra-arterial injection of trout STC. Basal plasma STC concentrations in freshwater and seawater eels did not differ but the STC secretion rate and metabolic clearance rate in seawater eel were 70–75% higher than in FW eel. The increased STC distribution space in seawater eels suggests that the STC receptor density was increased. STC had a higher hypocalcemic potency in seawater than in freshwater eels. These observations support the hypothesis that seawater fish require more hormonal control over transcellular influx of calcium than freshwater fish.To whom correspondence should be addressed.     

中国兰花不同品种线粒体代谢微量热分析

采用线粒体代谢微量热法,对中国兰花的春兰和蕙兰两个种间的10个品种进行微量热分析.得到春兰5个品种线粒体代谢总生热量(Q)值分别为:61.408、57.469、74.701、54.559和60.453J:蕙兰5个品种线粒体代谢总生热量(Q)值分别为:112.857、96.412、90.830、103.171和97.123J.结果显示,春兰与蕙兰两个种间线粒体代谢总生热量(Q)值存在明显差异,种内不同品种间线粒体代谢总生热量(Q)值变化较小,且春兰和蕙兰两个种间产热模式不同.